{
  "bibcode": "2002GCN..1242....1H",
  "body": "A. Henden (USRA/USNO) reports on behalf of the USNO GRB team:\n\nWe have acquired UBVRcIc all-sky photometry for\nan 11x11 arcmin field that is approximately centered on\nthe position of supernovae SN2002ap with the USNOFS 1.0-m telescope\non one photometric night.  Since the supernovae is expected\nto brighten further, exposures were short so that no star\nin the field is saturated.  We have placed the photometric\ndata on our anonymous ftp site:\nftp://ftp.nofs.navy.mil/pub/outgoing/aah/sequence/sn2002ap.dat\nThe current photometry has a potential external zero-point\nerror of less than two percent.  The astrometry in this file\nis based on linear plate solutions with respect to USNO-A2.0.\nThe internal errors are less than 100mas.\n\nAs conditions permit, this file will be extended to include\nmore photometric nights.  M74/NGC628 is a very popular object\nto photograph since it is large, bright and beautiful.\nA causual search of the public archives for several observatories\nindicates that there are dozens of deep plates and CCD images\nof the galaxy, many of which will include the supernovae\nregion.  For example, two such V-band images at NOFS have\napproximately the same depth and resolution as the V-band\nimage indicated by Smartt et al. (GCN 1240).  A simple\ndata-mining exercise should give a reasonable time history\nof any precursor over several decades.  Towards that end,\nwe will extend the photometry file down to about V=22 in\nthe near future.",
  "version": 2,
  "circularId": 1242,
  "editedOn": 1777052497911,
  "subject": "SN2002ap (SN/GRB?) UBVRI Field Photometry",
  "editedBy": "Judith Racusin at NASA/GSFC <judith.racusin@nasa.gov>",
  "email": "aah@nofs.navy.mil",
  "createdOn": 1012837995000,
  "submitter": "Arne A. Henden at USNO/USRA  <aah@nofs.navy.mil>",
  "eventId": "SN 2002ap"
}